Method and system for measuring blood coagulation time
First Claim
1. A method for measuring the end point of blood coagulation time comprising the steps ofproviding a mixture of a blood sample and a reagent,irradiating the mixture with light.detecting the amount of light scattered from the irradiated mixture and producing an electrical signal representative thereof, anddetermining from said electrical signal a first time at which the most rapid change in the electrical signal is occurring and then determining as the end point at a time prior to said first time the time at which a change which is 1/n that of the most rapid change occurred, where n is greater than 1.
0 Assignments
0 Petitions
Accused Products
Abstract
A blood coagulation time measuring method comprising irradiating a mixture of blood plasma and reagent with a beam of specified amount of light, detecting changes in the amount of light scattered by the mixture, converting the resulting scattered light output signals to digital form at specified time interval, feeding the digital data to a computer, computing the difference between each input value and the input value immediately adjacent thereto with respect to time and storing the results, and determining the time, prior to the time at which a maximum difference value is obtained, at which a computed difference value corresponding to 1/n of the maximum difference value is obtained. The time thus determined is the end point of the coagulation time. A system for practicing this method is also disclosed.
-
Citations
8 Claims
-
1. A method for measuring the end point of blood coagulation time comprising the steps of
providing a mixture of a blood sample and a reagent, irradiating the mixture with light. detecting the amount of light scattered from the irradiated mixture and producing an electrical signal representative thereof, and determining from said electrical signal a first time at which the most rapid change in the electrical signal is occurring and then determining as the end point at a time prior to said first time the time at which a change which is 1/n that of the most rapid change occurred, where n is greater than 1.
-
4. A system for measuring the end point of blood coagulation time comprising:
-
a cell for containing a mixture of blood plasma and a reagent, means for irradiating the mixture with an amount of light, means for detecting the amount of light scattered by the irradiated mixture and producing an electrical output signal representative thereof, means for measuring at predetermined times the rate of change of said output signal corresponding to the rate of change of the scattered light, means for determining a first time at which the maximum rate of change of the output signal takes place and for determining as the end point of the coagulation a time prior to said first time at which the rate of change of the output signal is 1/n that of the maximum rate of change, where n is greater than 1. - View Dependent Claims (5, 6, 7, 8)
-
Specification